Kyushu University Academic Staff Educational and Research Activities Database
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TODA HIROYUKI Last modified date:2020.09.10

Graduate School
Undergraduate School

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 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
Doctor of Engineering
Field of Specialization
Strength of Materials, Mechanical Properties of Materials
Outline Activities
I have lead a research group exploring materials strength and characterisation in 3D/4D. My research is in the field of deformation, fracture and fatigue on a wide range of structural/functional materials. A major focus is the exploration of the microstructure and the microstructure-property relations of such materials utilizing synchrotron X-ray microtomography at the third generation facilities, in particular the development of advanced 3D/4D measurements of stress/strain, crack-driving forces, chemical composition and crystallographic information in high density together with their applications to various issues in materials and mechanical engineerings. Recently we have proposed a new concept entitled "Reverse 4D Materials Engineering", in which the complex morphologies of existing materials is taken into account to realize a paradigm shift in materials development for structural/functional materials. We are also in charge of the development of new innovative aerospace materials that is based on a real fracture behavior that has been achiebved by applying the above-mentioned techniques.
Research Interests
  • 3D / 4D mesoscale materials science developed by ultrahigh magnification X-ray microscope
    keyword : Synchrotron radiation, Microtomography, Mechanical properties, Structural materials, Imaging CT, X-ray microscopy
  • Science of fatigue and fracture: Three-dimensional analyses of crack-tip using synchrotron radiation
    keyword : Synchrotron radiation, Microtomography, fatigue fracture, Tracking, Strain, Crack driving force, Mapping, Titanium alloys
  • Optimisation of microstructures in aluminium alloys via hydrogen partitioning control
    keyword : Synchrotron radiation, Microtomography, Mechanical properties, Hydrogen trapping, Hydrogen embrittlement, Pore, Tracking, Strain, Mapping, Aluminum alloys
  • Image-based analyses in 3D/4D and their application to structural materials
    keyword : Synchrotron radiation, Microtomography, Mechanical properties, Structural materials, Tracking, Strain, Chemical concentration, Crack driving force, Mapping, Steels, Aluminum alloys
  • Development of new innovative aerospace materials
    keyword : Synchrotron radiation, Microtomography, Mechanical properties, Structural materials, Hydrogen, Pore, 3D/4D analyses
  • A New Concept Breakthrough in Materials Development: Reverse 4D Materials Engineering
    keyword : Synchrotron radiation, Microtomography, Mechanical properties, Structural materials, Optimization, Coarsening, Image-based simulation
  • Crystallographic deformation behaviors of polycrystalline materials
    keyword : Synchrotron radiation, Microtomography, X-ray difffraction, Polycrystalline materials, Crystallographic orientation, Deformation, Fracture, Damage, Structural materials
Academic Activities
1. T. Tsuru, K. Shimizu, M. Yamaguchi, M. Itakura, K. Ebihara, A. Bendo, K. Matsuda, H. Toda, Hydrogen-accelerated spontaneous microcracking in high-strength aluminium alloys, Scientific reports, 10.1038/s41598-020-58834-6, 10, 1, 2020.04.
2. H. Su, H. Toda, K. Shimizu, K. Uesugi, A. Takeuchi, Y. Watanabe, Assessment of hydrogen embrittlement via image-based techniques in Al–Zn–Mg–Cu aluminum alloys, Acta Materialia, 10.1016/j.actamat.2019.06.056, 176, 96-108, 2019.09.
3. H. Su, H. Toda, R. Masunaga, K. Shimizu, H. Gao, K. Sasaki, Md S. Bhuiyan, K. Uesugi, A. Takeuchi, Y. Watanabe, Influence of hydrogen on strain localization and fracture behavior in Al–Zn–Mg–Cu aluminum alloys, Acta Materialia, 10.1016/j.actamat.2018.08.024, 159, 332-343, 2018.10.
4. H. Toda, A. Takijiri, M. Azuma, S. Yabu, K. Hayashi, S. Dowon, M. Kobayashi, K. Hirayama, A. Takeuchi, K. Uesugi, Damage micromechanisms in dual-phase steel investigated with combined phase- and absorption-contrast tomography, ACTA MATERIALIA, 10.1016/j.actamat.2017.01.010, 126, 401-412, 2017.03, SPring-8を利用したX線CTを用いれば、結晶粒界にある粒子が鮮明に3D観察できることに着目した。このような粒子は、金属が変形し、破壊していく過程でも常に結晶粒界に位置する為、結晶粒界の粒子の情報を使えば、個々の結晶の形を4Dで求めることができると発想した。3Dイメージング法にX線回折法を組み合わせることで、多結晶組織の結晶学的変形を解析できる手法として完成した。また、この手法を実用的な構造材料に適用できるレベルにまで高精度化することに成功した。.
5. H. Toda, T. Kamiko, Y. Tanabe, M. Kobayashi, D.J. Leclere, K. Uesugi, A. Takeuchi, K. Hirayama, Diffraction-amalgamated grain boundary tracking for mapping 3D crystallographic orientation and strain fields during plastic deformation, ACTA MATERIALIA, 10.1016/j.actamat.2016.01.072, 107, 310-324, 2016.04, SPring-8を利用したX線CTを用いれば、結晶粒界にある粒子が鮮明に3D観察できることに着目した。このような粒子は、金属が変形し、破壊していく過程でも常に結晶粒界に位置する為、結晶粒界の粒子の情報を使えば、個々の結晶の形を4Dで求めることができると発想した。3Dイメージング法にX線回折法を組み合わせることで、多結晶組織の結晶学的変形を解析できる手法として完成した。また、この手法を実用的な構造材料に適用できるレベルにまで高精度化することに成功した。.
6. H. Li, H. Toda, K. Uesugi, A. Takeuchi, Y. Suzuki, M. Kobayashi, Application of diffraction-amalgamated grain boundary tracking to fatigue crack propagation behavior in high strength aluminum alloy, Materials Transactions, 10.2320/matertrans.M2014340, 56, 3, 424-428, 2015.03.
7. H. Toda, P. C. Qu, S. Ito, K. Shimizu, K. Uesugi, A. Takeuchi, Y. Suzuki, M. Kobayashi, Formation behaviour of blister in cast aluminium alloy, International Journal of Cast Metals Research, 27, 6, 369-377, 2014.06.
8. H. Toda, H. Oogo, K. Horikawa, K. Uesugi, A. Takeuchi, Y. Suzuki, M. Nakazawa, Y. Aoki, M. Kobayashi, The true origin of ductile fracture in aluminum alloys, Metallurgical and Materials Transactions A, 10.1007/s11661-013-2013-3, 45A, 2, 765-776, 2014.02.
9. C. Gupta, H. Toda, T, Fujioka, M. Kobayashi, K. Uesugi, A. Takeuchi, Y. Suzuki, Micro-pore development phenomenon in hydrogen pre-charged aluminum alloy studied using synchrotron X-ray micro-tomography, Applied Physics Letters, 10.1063/1.4826274, 103, 17, 171902, 2013.10.
10. H. Toda, Y. Ohkawa, T. Kamiko, T. Naganuma, K. Uesugi, A. Takeuchi, Y. Suzuki, M. Kobayashi, Grain boundary tracking technique: four-dimensional visualisation technique for determining grain boundary geometry with local strain mapping, Acta Materialia, 61, 14, 5535-5548, 2013.08, SPring-8を利用したX線CTを用いれば、結晶粒界にある粒子が鮮明に3D観察できることに着目した。このような粒子は、金属が変形し、破壊していく過程でも常に結晶粒界に位置する為、結晶粒界の粒子の情報を使えば、個々の結晶の形を4Dで求めることができると発想した。2011年度には、この手法を実用的な構造材料に適用できるレベルにまで高精度化することに成功した。この手法により、多結晶材料中のすべての結晶粒の形状の変化を時間を遡りながら4Dで観察することができるようになった。この成果は、金属材料工学では最も権威のある英文誌であるアクタ・マテリアリア誌に掲載が決定された。.
11. H. Toda, K. Tsubone, K. Shimizu, K. Uesugi, A. Takeuchi, Y. Suzuki, M. Nakazawa, Y. Aokic, M. Kobayashi, Compression and recovery micro-mechanisms in flexible graphite, Carbon, 59, 184-191, 2013.08.
12. H. Toda, Z. A. B. Shamsudin, K. Shimizu, K. Uesugi, A.Takeuchi, Y. Suzuki, M. Nakazawa, Y. Aoki, M. Kobayashi, Cavitation during high-temperature deformation in Al-Mg alloys, Acta Materialia, 10.1016/j.actamat.2013.01.012, 61, 7, 2403-2413, 2013.04, 過飽和な水素がアルミニウム内に分子状水素として排出され、ポアとして知られるミク ロ欠陥が生成されることに着目した。これらが常温の変形・破壊を支配することは、我々の最近の研究によって明らかにされている。従来、高 温での変形や加工では、粒界三重点でポアが発生して損傷に至るとされている。この研究では、高温変形の3D/4Dその場観察を行い、破壊起点を特定した。その結果、高温での変形や加工では、過飽和 な水素に起因する内在ポアの成長と従来の損傷機構(粒界三重点などでのポア発生)が競合し、前者が破壊を規定することが示された。.
13. D. Seo, F. Tomizato, H. Toda, K. Uesugi, A. Takeuchi, Y. Suzuki, M. Kobayashi, Spatial resolution of synchrotron x-ray microtomography in high energy range: Effect of x-ray energy and sample-to-detector distance, Applied Physics Letters, 10.1063/1.4773239, 101, 26, 261901, 2012.12, これまで、鉄鋼材料のX線 による3D/4Dイメージングは、空間分解能が理論分解能より1~2桁低く、実用にはならなかった。この研究では、大型放射光施設SPring-8の活用と様々な撮像条件の最適化により、鉄鋼でもほぼ理論分解能での撮像が可能に なった。これは、主にはこれまで知られていなかったX線前方散乱による大きな悪影響を避けることで達成された。この研究の成果により、鉄鋼材料でも、熱処理や加工時の組織変化、変形・破壊・疲労破壊などの3D/4Dその場観察やその解析が可能になった。.
14. H. Toda, S. Masuda, R. Batres, M. Kobayashi, S. Aoyama, M. Onodera, R. Furusawa, K. Uesugi, A. Takeuchi, Y. Suzuki, Statistical assessment of fatigue crack initiation from sub-surface hydrogen micropores in high-quality die-cast aluminum, Acta Materialia, 10.1016/j.actamat.2011.04.049, 59, 12, 4990-4998, 2011.07.
15. H. Toda, E. Maire, S. Yamauchi, H. Tsuruta, T. Hiramatsu, M. Kobayashi, In situ observation of ductile fracture using X-ray tomography technique, Acta Materialia, 10.1016/j.actamat.2010.11.065, 59, 5, 1995-2008, 2011.03.
16. H. Toda, T. Yamaguchi, M. Nakawaza, Y. Aoki, K. Uesugi, Y. Suzuki, M. Kobayashi, Four-Dimensional Annihilation Behaviors of Micro Pores during Surface Cold Working, Materials Transactions, 10.2320/matertrans.M2010069, 51, 7, 1288-1295, 2010.07.
17. H. Toda, T. Nishimura, K. Uesugi, Y. Suzuki, M. Kobayashi, Influence of high-temperature solution treatments on mechanical properties of an Al-Si-Cu aluminum alloy, Acta Materialia, 10.1016/j.actamat.2009.11.044, 58, 6, 2014-2025, 2010.04.
18. H. Toda, K. Minami, K. Koyama, K. Ichitani, M. Kobayashi, K. Uesugi, Y. Suzuki, Healing behavior of preexisting hydrogen micropores in aluminum alloys during plastic deformation, Acta Materialia, 10.1016/j.actamat.2009.06.012, 57, 15, 4391-4403, 2009.09.
19. H. Zhang, H. Toda, P.C. Qu, Y. Sakaguchi, M. Kobayashi, K. Uesugi, Y. Suzuki, Three-dimensional fatigue crack growth behavior in an aluminum alloy investigated with in situ high-resolution synchrotron X-ray microtomography, Acta Materialia, 10.1016/j.actamat.2009.03.036, 57, 11, 3287-3300, 2009.06.
20. H. Toda, T. Hidaka, M. Kobayashi, K. Uesugi, A. Takeuchi, K. Horikawa, Growth behavior of hydrogen micropores in aluminum alloys during high-temperature exposure, Acta Materialia, 10.1016/j.actamat.2009.01.026, 57, 7, 2277-2290, 2009.04.
21. L. Qian, H. Toda, K. Uesugi, M. Kobayashi, T. Kobayashi, Direct observation and image-based simulation of three-dimensional tortuous crack evolution inside opaque materials, Physical Review Letters, 100, 11, 115505, 2008.11.
22. A. Weck, D.S. Wilkinson, E. Maire, H. Toda, Visualization by X-ray tomography of void growth and coalescence leading to fracture in model materials, Acta Materialia, 10.1016/j.actamat.2008.02.027, 56, 12, 2919-2928, 2008.07.
23. M. Kobayashi, H. Toda, Y. Kawai, T. Ohgaki, K. Uesugi, D.S. Wilkinson, T. Kobayashi, Y. Aoki, M. Nakazawa, High-density three-dimensional mapping of internal strain by tracking microstructural features, Acta Materialia, 10.1016/j.actamat.2007.12.058, 56, 10, 2167-2181, 2008.06.
24. L. Li, H. Toda, T. Ohgaki, M. Kobayashi, T. Kobayashi, K. Uesugi, Y. Suzuki, Wavelet-based local region-of-interest reconstruction for synchrotron radiation X-ray microtomography, Journal of Applied Physics, 102, 114908-1-9, 2007.01.
25. H. Toda, K. Uesugi, A. Takeuchi, K. Minami, M. Kobayashi, T. Kobayashi, Three-dimensional observation of nanoscopic precipitates in an aluminum alloy by microtomography with Fresnel zone plate optics, Applied Physics Letters, 10.1063/1.2359288, 89, 14, 143112, 2006.10.
26. T. Ohgaki, H. Toda, M. Kobayashi, K. Uesugi, M. Niinomi, T. Akahori, T. Kobayashi, K. Makii, Y. Aruga, In situ observations of compressive behaviour of aluminium foams by local tomography using high-resolution X-rays, Philosophical Magazine A, 10.1080/14786430600724454, 86, 28, 4417-4438, 2006.10.
27. L. Qian, H. Toda, K. Uesugi, T. Kobayashi, T. Ohgaki, M. Kobayashi, Application of synchrotron x-ray microtomography to investigate ductile fracture in Al alloys, Applied Physics Letters, 10.1063/1.214208, 87, 24, 241907, 2005.12.
28. Y.L. Zhou, M. Niinomi, T. Akahori, H. Fukui, H. Toda, Corrosion resistance and biocompatibility of Ti-Ta alloys for biomedical applications, Materials Science & Engineering. A, 10.1016/j.msea.2005.03.032, 398, 1-2, 28-36, 2005.05.
29. H. Toda, J. Katano, T. Kobayashi, T. Akahori, M. Niinomi, Assessment of thermo-mechanical fatigue behaviors of cast Al-Si alloys by experiments and multi-step numerical simulation, Materials Transactions, 46, 1, 111-117, 2005.01.
30. K.H. Khor, J.-Y. Buffiere, W. Ludwig, H. Toda, H.S. Ubhi, P.J. Gregson, I. Sinclair, In situ high resolution synchrotron x-ray tomography of fatigue crack closure micromechanisms, Journal of Physics: Condensed Matter, 10.1088/0953-8984/16/33/012, 16, 33, S3511-S3515, 2004.08.
31. H. Toda, I. Sinclair, J.-Y. Buffiere, E. Maire, K.H. Khor, P. Gregson, T. Kobayashi, A 3D measurement procedure for internal local crack driving forces via synchrotron X-ray microtomography, Acta Materialia, 10.1016/j.actamat.2003.11.014, 52, 5, 1305-1317, 2004.03.
32. H. Toda, I. Sinclair, J.-Y. Buffiere, E.Maire, T. Connolley, M. Joyce, K.H. Khor, P. Gregson, Assessment of fatigue crack closure phenomenon in damage tolerant aluminium alloy by in-situ high-resolution synchrotron X-ray microtomography, Philosophical Magazine A, 83, 21, 2429-2448, 2003.07.
Membership in Academic Society
  • The Japan Institute of Light Metals
  • Japan Foundry Engineering Society
  • The Iron and Steel Institute of Japan
  • The Japan Institute of Metals and Materials
  • The Japan Society of Mechanical Engineers
  • The Society of Materials Science
  • JSPS 176th Committee
  • JSPS 147th Committee
  • SPring-8 users community
  • SPring-8 X-ray Micro/Nano-tomography Research Group
  • Simulation of deformation texture evolution in aluminum alloy based on local strain obtained by synchrotron 3D measurement
  • Fatigue Behavior Analysis of Spheroidal Graphite Cast Iron via High Resolution 4D Imaging
  • The publication prize of the Worshipful Company of Founders for the best paper published in the International Journal of Cast Metals Research (IJCMR) has been awarded to Hiroyuki Toda et al. for their paper entitled, ‘Formation behaviour of blister in cast aluminium alloy' (IJCMR 2014, Vol. 27, p.369).
Educational Activities
I am teaching three courses on "Strength of Materials" in the bachelor course, which cover basic theories of strength of materials. I am also in charge of student experiments (mechanical testing). In the graduate school, I am teaching a course entitled "Evaluation of structural materials", "Strength of automobiles" and Introduction to automotive science". I also supervise several graduate students, several bachelor students and some pos-docs in the laboratory.